Figure 5

Effect of beclomethasone on intracellular bacterial growth and cell death. Infection was performed in Tg(mpeg1:eGFP) embryos at 28 hpf, a TUNEL assay was performed at 48 hpi, and the CHT region of the embryos was imaged using confocal microscopy. (A) The percentage of Mm clusters that were inside macrophages based on colocalization with the green fluorescent signal from eGFP. Statistical analysis was performed by two-tailed t-test. In the beclomethasone-treated group, the percentage of Mm clusters inside macrophages was significantly lower compared to the vehicle-treated group. (B) The percentage of TUNEL-positive Mm clusters. Statistical analysis by two-tailed t-test showed that the beclomethasone-treated group had a significantly lower percentage of TUNEL+ Mm clusters. In panels (A, B), each data point represents a single embryo and the means ± s.e.m. of data accumulated from three independent experiments are shown in red. Statistical significance is indicated by: **P<0.01. (C) Representative confocal microscopy images of macrophage phagocytosis. Bacteria are shown in blue and macrophages in red. Arrowheads indicate intracellular bacterial clusters. Scale bar = 100 μm. (D) Representative confocal microscopy images of cell death (TUNEL+ cells in magenta) and Mm infection (bacteria in blue). Arrowheads indicate bacterial clusters overlapping with TUNEL+ cells. Scale bar = 100 μm.